Azure zone-redundant storage, which was previously in public preview, is now generally available.
Zone-redundant storage greatly simplifies development of highly available applications by replicating your data to different Availability Zones, with inserts and updates to data being performed synchronously across these Availability Zones. You can continue with read and write operations on your data even when one of the Availability Zones is unavailable or unrecoverable.
Availability Zones provide fault isolation through physical separation. Each zone consists of one or more datacenters with independent power, network and cooling. Consider zone-redundant storage for applications where highly available read and write access is required in an Azure region.
Starting 1st Jun 2018, generally available pricing will take effect. Preview pricing will continue until that date. For more details on zone-redundant storage—including regional availability, pricing and migration—see the documentation.